It is known that nickel in the form of plates or grids is used as the electrode material in such electrolysers particularly when they are suitable for producing hydrogen by electrolysis of an aqueous solution of concentrated potash.
It is also known that the voltage required to perform the electrolysis can be reduced by increasing the temperature of the electrolyte.
Nonetheless, while such an increase turns out to be beneficial up to a temperature of about 80.degree. to 100.degree. C., at higher temperatures the advantageous effect is noticeably less marked, particularly when taking account of the high current densities which are used in industrial electrolysers.
Preferred embodiments of the present invention mitigate the drawbacks outlined above.
The invention provides an electrolyser for an alkaline aqueous solution and having an anode and a cathode wherein at least the cathode is made of a ternary alloy of nickel-beryllium-titanium; the proportions of beryllium and titanium being respectively 1 to 3% and 0.1 to 1% by weight.
Preferably the operating temperature of the alkaline aqueous solution is at least 110.degree. C.
An embodiment of the invention is described by way of example with reference to the accompanying drawings.